47-21-21 REPUBLIC: (Was Service Note 1 of AD-769-2.) Applies to Model RC-3 Aircraft Serial Numbers 5 to 236, Inclusive.
Inspection required immediately and periodically as noted below.
Inspect two slots at upper end of each tip float strut (P/N 17W23001) very carefully for cracks. Slots are located inside of wing contour, therefore, struts must be removed from wing at upper attachment for proper inspection. If any cracks are present, strut shall be replaced prior to further operation. All struts without relief holes at ends of slots as recommended by manufacturer shall be inspected for cracks at 50-hour intervals.
(Republic Seabee Service Bulletin No. 12 covers this same subject.)